The purpose of this study is to compare the efficacy and safety of HOE901 with that of NPH human insulin when used with insulin lispro in subjects with type I diabetes over a period of 16 weeks. This study will be performed in subjects with type I diabetes, treated with insulin, with screening GHb of <12.0%. The comparison of HOE901 and NPH human insulin in terms of efficacy will be based on levels of GHb. Measurement of GHb is a clinically useful means of assesing glycemic control in diabetes. GHb values reflect blood glucose levels over the previous 2-3 months. For the secondary objectives, fasting glucose, variability of fasting glucose, hypoglycemia and pharmacoeconomics will be compared between the two treatment groups. Safety will be assessed on the bases of an analysis of clinical events, standard clinical events, standard clinical chemistry and hematology findings and determination of E. coli antibodies and insulin antibodies.